RARE-EARTH ELEMENT- AND YTTRIUM-BEARING PEGMATITE DIKES NEAR DORA BAY, SOUTHERN PRINCE OF WALES ISLAND

By James C. Barker and Cheryl Mardock

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * OFR 19-90

UNITED STATES DEPARTMENT OF THE INTERIOR

Manuel Lujan, Jr., Secretary

BUREAU OF MINES

T S Ary, Director CONTENTS

Page

Abstract ...... 1 Introduction ...... 2 Land status and access ...... 4 Geologic setting ...... 4 Regional geology ...... 4 Intrusive rocks ...... 4 Pegmatite dikes ...... 7 Mineralogy and Petrography of the Pegmatite dikes ...... 8 Sampling methods and analytical techniques ...... 10 Mineralization ...... 10 Resources ...... 20 Heavy survey ...... 20 Discussion and conclusions ...... 22 References ...... 25 Appendix A. - Rock sample multi-elements analyses ...... 26 Appendix B. - Heavy mineral concentrates multi-element analyses... 35

ILLUSTRATIONS

1. Location of the Dora Bay intrusive complex on southern Prince of Wales Island ...... 3 2. Geology, mineralized pegmatite dikes, and sample locations near Dora Bay: Insert shows lateral zoning of REE-Y-Cb with respect to SiO 2 between pegmatites and -dikes ...... 5 3. SEM backscatter image of intergrown (bright mineral in center) with thalenite (cream colored mineral on left) and bastnaesite (darker gray ) in a matrix of and calcite. Magnification is 200X ...... 9 4. Location of panned heavy mineral concentrates near Dora Bay... 11 5. Correlation of REE+Y to SiC 2 in mineralized pegmatite dikes... 19 6. Comparison of REE composition of Dora Bay pegmatite dikes to mineral deposits at Bokan Mountain and other major U.S. REE sources ...... 23

TABLES

1. Major oxide analyses and normative mineralogy (in pct) of whole rock samples from the Dora Bay complex ...... 6 2. Principal REE and Cb-bearing minerals identified at Dora Bay.. 8 3. Analytical methods and detection limits ...... 12 4. Pegmatite dikes and wallrock sample results ...... 13 5. Eudialyte-bearing pegmatite sample results ...... 16 6. Other sample results ...... 17 7. Volume and weights of heavy mineral concentrates, and normalized yttrium in panned samples from the Dora Bay area.. 21

i UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT

cm centimeter cps count per second ft foot 9 gram in inch lb pound lb/yd 3 pound per cubic yard mg milligram mi mile pct percent ppm part per million ppb part per billion um micrometer, micron st short ton yd3 cubic yard RARE-EARTH ELEMENT AND YTTRIUM-BEARING PEGMATITE DIKES NEAR DORA BAY, SOUTHERN PRINCE OF WALES ISLAND

By James C. Barkeri! and Cheryl Mardock2/

ABSTRACT

Yttrium and rare-earth element pegmatite dikes are associated with a peralkaline granitic and nephelene complex near Dora Bay on southern Prince of Wales Island. Mineralized dikes were mapped and sampled during USBM investigations in 1987 and 1988.

Coarse-grained pegmatite dikes, which emanated as late-stage magmatic fluids from the intrusion, further evolved into vein-dikes and ultimately silica-rich veins. The dikes can be traced up to two miles along a north- south zone. Lithophile elements exhibit a pronounced zonation in vein-dikes and veins that are distal to the Dora Bay complex with increasing values correlating with increasing distance from the complex. The pattern of mineralization suggests very late stage magmatic fluids containing the incompatable lithophile elements were injected into a preexisting north-south fracture zone.

REE mineralogy exhibit fine-graired intergrowths of principally thalenite and bastnaesite with lessor monazite and eudialyte. contains most of the columbium values and is commonly associated with the dikes.

Estimates of inferred and hypothetical resource tonnage range from 1.7 X 106 to 8.5 X 106 st for two deposits. Contained REO (including yttrium) averages 0.5 pct and ranges up to 2.0 pct. Deposits are of polymineralic composition and about half of this resource comprises the heavy yttrium subgroup.

1/Supervisory physical scientist, Alaska Field Operations Center, Fairbanks, Alaska. 2/Geologist, Albany Research Center, Albany, Oregon.

1 INTRODUCTION

Southern Prince of Wales Island, in southeast Alaska (fig. 1), is host to a trend of sodium-rich intrusive complexes and associated radioactive mineral occurrences that contain varying amounts of rare-earth elements (REE), columbium ().!/, and other lithophile metals (1, 2)4!. During investigations in 1987 and 1988 by the Bureau of Mines, mineralized showings near Dora Bay were found to be among this trend of occurrences. These studies are being conducted as part of the Bureau's effort to identify and assess Alaskan reserves or resources of certain critical and strategic minerals which could be extracted during periods of prolonged national shortages. On southern Prince of Wales Island, the Bureau has recently conducted other reconnaissance investigations at Stonerock Bay, Mclean Arm, Bokan Mountain, Mcira Sound, and Cholmondeley Sound.

3/The element 'Niobium' is also referred to as 'Columbium' in the context of a commercial commodity. 4/Underlined numbers in parentheses refer to the list of references preceding the appendices at the end of this report.

Columbium is used widely as a hardening alloy in high-strength, low-alloy steels. It is considered of strategic importance to the United States (U.S.) because of its application in national defense and petroleum industries, and developing uses in advanced technology. At present the country is entirely reliant on foreign sources of the metal (3). The REE are a group of 15 chemically similar elements consisting of the lanthanide-series, atomic numbers 57 through 71. Yttrium, whose atomic number is 39, is often included with the REE because of similar chemical properties. These elements are often subdivided into two groups: 1) the light REE (cerium subgroup) consists of elements with atomic numbers 57 through 63; and 2) the heavy REE (yttrium subgroup) consists of elements with atomic numbers 39 and 64 through 71. The REE have wide and increasing applications as catalysts for the petrochemical industry, steel alloys, lighting, phosphors, glass and optics, and electronics (4). New alloy compositions for magnets utilizing certain REE have led to improved magnetic field strengths. Recent research in the fields of superconductors and metal-oxide ceramics has been dramatically advanced by the use of various REE compounds, particularly yttrium. At the present time, however, these potential new uses are still in early research and development stages and have not yet resulted in a significant increase in demand for REE. The U.S. is self-reliant in the lighter REE, however, most of the heavy REE, including yttrium are imported. Worldwide, most of the production of the heavy REE occurs as a by-product to and titanium placer mining. There has been no previous documented evaluation of the REE or columbium resource potential near Dora Bay. However, of significance is the identification by Herreid and others (5) of eudialyte in zirconium mineralized rubble on a beach of Dora Bay. Eudialyte is a zirconium mineral often associated with REE deposits elsewhere in the world. At Dora Bay, Eberlein and others (6) further noted its occurrence in a and syenite intrusion they mapped immediately southwest of Dora Bay.

2 Figure 1. - Location of the Dora Bay intrusive complex on southern Prince of Wales Island.

3 The REE-columbium deposits near Dora Bay described in this report are not of sufficient grade to be presently economic to mine as compared to other deposits in the world. However, much of the world's REE resource potential is comprised of only the lighter REE, whereas most deposits on southern Prince of Wales Island, including those at Dora Bay, also contain the heavy yttrium subgroup. Therefore, the results of the investigation at Dora Bay are presented in the following report.

LAND STATUS AND ACCESS

The investigation area near Dora Bay lies in the Craig A-1 and A-2 quadrangles and is located in the federally managed Tongass National Forest. Certain land entitlement claims have been made in the vicinity by the SeaAlaska Native Corp. Final disposition of those claims is continuing. Elsewhere the area is designated multiple-use by the Forest Service and is open to mineral entry. Dora Bay is a well-sheltered, relatively deep bay that is readily accessible by either boat or float planes. A foot trail leads from the head of the bay to Dora Lakes where a canoe was used during this project to gain access to areas of interest. During the field examination in 1987-88 on-going logging operations were continuing to expose additional outcrops of bedrock. Logging roads now provide access to the region immediately west of the project area.

GEOLOGIC SETTING

Regional Geology

Bedrock geology of the Dora Bay area is composed of volcaniclastic and metasedimentary rocks that have been intruded by a peralkaline granitic complex with phases of syenite, diorite, and alkaline . The clastic rocks have been included in the Wales Group by Eberlein and others (6), and comprise pre-Middle Ordovician to Precambrian (?), predominantly andesitic to basaltic marine volcanics, mudstones, and shales. Marble is locally interlayered in the Wales Group. Age of the Wales Group has been assigned on the basis of structural relationships with other rock units outside of the study area; no fossil record has been found. Near Dora Bay tan-colored pelitic sediments are generally metamorphosed to . Foliation in the is believed to represent original bedding (6). Between Dora Bay and the South Arm of Cholmondeley Sound, intrusive bodies of eudialyte-bearing and associated pegmatites have been mapped by Eberlein and others at 1:250,000 scale (6).

Intrusive Rocks

The Dora Bay peralkaline intrusive complex, informally named for this report, consists predominantly of medium-grained peralkaline (?) granite and hornblende syenite, with alkaline granite and diorite variants. Major oxide chemistry and CIPW normative mineralogy of representative chip samples of the are given in table 1. The principal intrusive phases are classified on the basis of the rock chemistry and field observations. The complex has also given rise to late stage pegmatites and dikes that cut both the intrusive rocks and the Wales Group metasediments.

4

Rubble and outcrop mapping (fig. 2) indicates that the complex is a north-south trending, 10,000-ft long, sinuous sheet-like body. The complex, as presently exposed, conforms approximately to an inferred north-south fault shown on the regional geologic map by Eberlein and others (6). The configuration of an aerial magnetic anomaly of 1,047 gamma T7) occurring about one mi west of north Dora Lake further suggests a westerly dip of the complex. Peralkaline granite boulders were found in a creek bed in this vicinity and also found at several beach localities on the east side of South Anm Cholomondeley Sound. Geologic reconnaissance (during this project) of the region immediately west of figure 2 encompassing the aerial magnetic anomaly observed silicified, highly altered metasediments (?)that are intruded by a fine-grained diorite. It could not be ascertained whether this fine-grained diorite, which was not found to contain pegmatite or syenite phases, is in any way genetically associated with the Dora Bay complex. Further to the west on the west side of the South Arm of Cholomondeley Sound, numerous alkaline carbonate basaltic dikes cut the Wales Group schist (table 1).

Pegmatite Dikes

Several types or phases of dikes are included under the classification of pegmatites at Dora Bay. These include:

1) coarse-grained tabular bodies, up to 13-ft thick, of quartz- composition with minor riebeckite, , and zircon; a halo of pyritic and chloritic alteration is generally present in the country rock; 2) vein-dikes./, commonly 1- to 3-ft thick, that exhibit hydrothermal alteration minerals typical of veins (e.g. quartz banding, sericite, rhodochrosite, , and sphalerite), but also an intrusive selvage, wallrock alteration to hornfels, and pegmatitic quartz and albite core; and 3) siliceous, manganese-stained, noticeably more radioactive veins, less than 1.2 ft thick, that appear gradational along strike from the vein-dikes.

5/For this report, a vein-dike is defined as a pegmatitic intrusion that has characteristics of both a vein and dike (7).

The coarse-grained pegmatites cut both the intrusive complex and the country rocks nearby, whereas the vein-dikes occur only in the country rock. The siliceous veins are more distal yet from the intrusion. Within the country rock, but proximal to the intrusion, a transition zone occurs where both coarse pegmatites and vein-dikes can be observed subparallel to each other in the same outcrop (see insert fig. 2), thereby indicating they are the result of somewhat chemically different and repeated phases of dike emplacement along the same structural zone. Where they cut metasediments, the pegmatite dikes tend to be long, tabular, locally bifurcating bodies whereas in the intrusion itself, they are diffuse irregular masses, generally too small to map. Locally they form minor intrusive phases commonly containing eudialyte. Further away from the intrusive complex where the dikes are more vein-like, the individual veins and vein-dikes bifurcate and splay over a 7 widening area of at least several hundred feet (e.g. sample locations 6-11, fig. 2).

Pegmatite dikes exhibit local variations of dip and strike, but overall they form a subparallel west-dipping system of tabular bodies that strike north-south, parallel to the trend of the intrusive complex (fig. 2). The coarse-grained pegmatites feature numerous thin spur dikes that extend up to 10 ft into the hanging and footwalls. Spur dikes dip perpendicular to a principal dike yet strike subparallel to it.

MINERALOGY AND PETROGRAPHY OF THE PEGMATITE DIKES

Results of microprobe, scanning electron microscopy, and transmitted- light microscopy studies indicate that the rare-earth mineralogy of the Dora Bay complex is very similar to that of the Bokan Mountain pegmatitic and quartz-albite dike system. The predominant rare-earth minerals observed are thalenite and bastnaesite (table 2). The rare earth minerals are intricately intergrown. Figure 3 is a scanning electron backscatter (SEM) photomicrograph of a rare-earth mineral grain intergrowth containing monazite, bastnaesite, and thalenite in a matrix of quartz and calcite. Eudialyte 2 [Na4(Ca,Ce)2(Fe +,Mn,Y)ZrSi8 O22(OH,Cl) 2] was not detected in the samples examined by SEM, however, the presence of Cl, detected by microprobe, indicates that this mineral is probably also present; few other rare-earth minerals contain Cl. Locally eudialyte is abundant (3-15 pct) in restricted phases of the intrusion, however, in the field it was not observed to occur in the veins extending beyond the intrusive margins.

Table 2. - Principle REE- and Cb-bearing minerals identified at Dora Bay

Major I Minor Thalenite Monazite Bastnaesite Eudialyte Euxenite

Optical, radiometric, and microhardness tests indicate the presence of euxenite which likely accounts for the Cb found by geochemical analyses. Other ore minerals detected during preliminary studies include zircon, allanite, and galena. Zircon occurs as euhedral and in unique quartz crystals up to 2 cm long filled with pink zircon. Zircon replaced quartz crystals were observed as selvages and center-core bands within some vein dikes near sample nos. 6-11 (fig 2). Gangue minerals of quartz, rhodochrosite, , acmite (aegirine), riebeckite, calcite, and chlorite were identified optically. Riebeckite and aegirine are most common in the coarse grain pegmatites within or near the intrusion.

8 Figure 3. - SEM backscatter image of intergrown monazite (bright mineral in center) with thalenite (cream colored mineral on left) and bastnaesite (darker gray minerals) in a matrix of quartz and calcite. Magnification is 200X

9 SAMPLING METHODS AND ANALYTICAL TECHNIQUES

The Dora Bay area features precipitous, heavily forested slopes that lead directly down to tidewater. Although good bedrock exposure occurs at higher elevations, most of the areas of interest are associated with linear structural zones which are subject to erosion and lie at lower elevations near or within several hundred vertical feet of tidewater. Generally these lower slopes are mantled with avalanche debris and thick-tangled vegetation, thereby confining mapping and sampling to rubble supplemented with only rare outcrop. Consequently, sampling of surface exposures for the purpose of quantifying reserves or resources could not be undertaken on a routine basis. Unless otherwise noted in the text, sampling was done as a continuous line of chips across tabular bodies exposed either in outcrop or rubble. Rock samples were analyzed at a commercial laboratoryY/ for a package of 42 elements by a variety of analytical techniques listed in table 3.

6/Analyses by Nuclear Activation Services, Ann Arbor, Michigan.

Analytical results and rock sample descriptions are presented in tables 4-6. Complete analyses are listed in the appendices. In addition to the elements listed in table 3, a representative suite of rock samples were also analyzed for Pr, Gd, Tm, Dy, Ho, and Er by an ICP/mass spectrometry procedure by the same laboratory. This permitted a determination of the total REE content in samples representative of the Dora Bay deposits. A series of 37 heavy mineral concentrates were also collected in an attempt to detect the presence of additional mineral deposits that may be hidden by surficial cover. At each site (fig. 4) approximately one level-full 14-in gold pan of -3/8 in material was reduced by panning to a concentrate of predominantly heavy minerals. Concentrates were then weighed, pulverized, and analyzed for 34 elementsZ/ according to procedures listed in table 3.

7/Analyses by Bondar-Clegg, Inc., Lakewood, Colorado.

Original sample volumes, concentrate weights, and analytical results are listed in table 7. The heavy mineral data set was evaluated using Y as a path-finder element. Note that analytical results have been correlated by weight to the amount of recovered concentrate in mg. These normalized recovered weights of elemental Y in the original sample volumes can be compared between sample sites.

MINERALIZATION

A system of REE-Cb enriched pegmatite dikes can be traced intermittently from near the head of Dora Bay southward along the western margin of south Dora Lake (fig. 2). From the available exposures, it is apparent that there are a multitude of dikes comprising the system, the number of which

10 I;- ~~~~~~~~~~~ // ~~~~~~~~LEGEND

.. ~~~~~~~ ... , ~~~~~~~469 Sample location and number

.7 7,~~~~~~~~~V

0 1 2

/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~contourinterval 100 feet

Base adapted from U.S.G.S. 1:63.360 scale Graig (A-i) quadrangle

Figure 4. - Location of panned heavy mineral concentrates near Dora Bay. Table 3. - Analytical methods and detection limits ROCK SAMPLES I Analytical r Detection 1 1 Analytical F Detection Element(s) Method limit, ppm Element(s) Method limit, ppm Ag I DCP [ 0.5 1 Pr I ICP-MS I 0.1 1 As I NA I 2.0 Rb I XRF I 20 Au NA I .010 Sb I NA | .2 B I DCP I 100 I Sc NA | .1 Ba | XRF 10 Se NA I 3.0 Be DCP | 10.0 Sm I NA .1 Bi | DCP | .5 I Sr XRF I 20 Br NA 1.0 Ta NA 11.0 Cb I XRF 20 I Th I NA .5 Cd I DCP I .2 I Tm ICP-MS I 0.1 Ce I NA I 3.0 1 U I NA .5 Co I NA 1.0 V j DCP 100 Cr XRF I 10 I W NA 3.0 Cs NA I .5 I Y I XRF 20 Cu I DCP I .5 I Yb NA I .02 Dy ICP-MS 0.1 | Zn I DCP I .5 Er I ICP-MS I 0.1 I Zr I XRF I 20 Eu I NA I .2 I A1203 I XRF I 100 Ga ICP-MS 0.1 CaO XRF I 100 Ge DCP 100 Fe203 XRF I 100 Hf I NA | 1.0 1K20 I XRF I 100 Ho I ICP-MS 0.05 L01 XRF I 100 La NA .5 I MgO I XRF I 100 Lu NA 1.05 IMnO IXRF |100 Mn I DCP I 2.0 Na2O I XRF I 100 Mo NA I 5.0 P205 XRF 100 I Nd I NA I 5.0 I 5iO2 XRF I 100 Ni I DCP I 1.0 I TiO2 I XRF I 100 Pb DCP 12.0

PAN CONCENTRATED SAMPLES Analytical I Detection I I Analytical I Detection T Element(s) I Method I limit, ppm I Element(s) I Method I limit, ppm I Ag [NA 15.0 INd [NA 15.0 1 As NA I 2.0 I Ni I NA 200 Au I NA I 10 I Rb I NA I 20.0 Ba I NA I 150 Sb I NA I 0.2 Br I NA I 1.0 I Sc I NA I 0.1 Ce I NA I 3.0 I Se I NA I 3.0 Co I NA I 1.0 I Sm I NA 0.1 Cr NA 12.0 Ta NA 11.0 Cs I NA I 0.5 I Th I NA I 0.5 Eu ! NA I 0.2 I U I NA I 0.5 Hf I NA I 1.0 I W I NA I 3.0 La I NA 0.5 I Y I NA I 2.0 Lu NA I 0.1 Yb I NA 0.2 Mo I NA 5.0 I Zn I NA I 20.0 Na INA 100 1 DCP - Direct current plasma NA - Nuclear activation XRF - X-ray fluorescence ICP-MS - Inductively coupled plasma followed by mass spectrometry Samples prepared with fusion techniques 12 Table 4. - Pegmatite dikes and wallrock sample results, in pDm

I 11 [I I I I MIGHT REE (Cerium SubqrouD)IHEAVY REE (Yttrium Subgroup) I Map I IWidthil I I I I IT 1 I I I I 11 I I I I I I I-I-Total No. IField No.l (ft)II Cb I Th I U I Y I Zr 1I La I Ce I Pri Nd I SmIEull GdlTbl D Hol ErITmI YbLuI REE 1....126525....1 1.3 11 6201 2301 22136001 49001! 5811144012701 92912841711157817716541133132513611551171 5550 2....126432....I 0.1 1113001 971 77133001 460011151013090153011330131517211532160155611051251130112511411 8520 3....126426....1 0.5 1 4001 1101 18146001 230011 3741 85811301 378112913111342151157311331361144116711711 3588 4....126527....1 0.8 11 4101 2501 47122001 340011 479110001---1 408110812611---I--1---I---I---l--113011311 ---- 5....126528....1 0.3 11 3901 3001 42127001 990011 7121138012001 59011511351126714413791 881239131116812111 4305 6....126429....1 1.7 1! 1901 541 201160012500011 1791 5371 611 2001 581131111712012061 541179126118812811 1866 7....126431....1 3.0 11 1301 391 241140013000011 1861 5781---1 2241 4411011---1161---I---I---1--122313411 ---- 9....126428....1 1.5 11 1401 2401 16110001 460011 1931 5191---1 2451 5911411---1161---I---I---1--1 8311111 -- 10...126427....1 1.8 11 2701 3201 361210011800011 5521129011901 64411411361121114113111 771176126124913611 3980 11...126531....1 1.2 11 1201 1001 201220012100011 1631 5391 591 1851 511131111212512431 6812211341226!3311 1972 12...126510....1 4.5 11 1501 1101 231190011200011 1911 5831 661 2241 591141110212011951 521174125118012411 1909 13...126421....1 4.0 11 3101 361 18112001 600011 2081 5911---1 2601 7211811---1201---I---I---1--1 9011211 ---- 14...126458 ....1 2.5 1L 1301 861 311120011600011 1051 3951---1 971 331 911---1151---I---I---1--11371201-

Descriptions- 1.... Sample includes four Mn-quartz dikes in a 10-ft section of schist. Dikes range from 3 to 5-in thick, I other similar dikes in area; 500 cps. 2.... ISiliceous Mn-stained narrow dike striking N30 W; 500 cps. 3.... ISiliceous fine-grain dike with porphyritic flesh-colored (REE?) mineral. Dike strikes N5 W; 700 cps. 4....1Mn-stained siliceous dike with Degmatitic quartz core; 900 cDs. Numerous similar, adjacent, thinner I dikes 1 to 4-in thick. 5.... 14-in thick fine-grain dike with clots of zircon. 6....IBanded hornfels, pegmatite, and fine-grain siliceous material with aegirine and needle-like pink I mineral; 300 CDs. Zone is wider than the 20 in exposed for sampling and has Degmatitic quartz core. 7.... IWider zone in outcrop similar to above. 9.... Banded dike as above with pegmatite center core; 600 cps. 10... IBanded silica and pegmatite quartz with 3 bands of unidentified needle-like zirconium minerals; 600 cps. I Hornfels adjacent to selvage. 11... IBanded siliceous dike similar to sample 6 above, with accessory galena; 400 cps. 12... ICombined sample of 4 quartz dikes, 8-, 10-, 14-, and 24-in thick composed of crudely banded quartz, I albite, riebeckite (?), and unidentified pink zirconium mineral, porphyritic cores. 13... Swarm of intersecting narrow dikes I mm to 2 mm thick and 3 larger dikes 3- to 6-in thick cutting I chloritic and pyritic schist, striking S 20 E; 300-900 cps. Dike material estimated to be 40 pct of I sample. Sample is upper 4 ft of 25-ft wide outcrop of similar material. 14... Similar to above but lower in section; 600 CDs. Sample contains .64 Dpm Au.

13 Table 4. - Pegmatite dikes and wallrock sample results, in ppm - Continued

I T[II IL I GLIGHT REE (Cerium Subgroup)lHEAVY (Yttrium SqrouP) ____ Map I lWidthlH I I I I lI- I I I I I 1[ 1 1 1I 1 1 IIootal No. lField No.1 (ft)II Cb I Th I U I Y I Zr 11 La I Ce I Prl Nd I SmlEulI GdlTbl DyA Hol EriTml YblLuWl REE 15 ..126520....1 2.0 If 5701 1601 30112001 940011 537114701---1 I ---I--- --[11---I113115-- 16 ...26519 ....1 3.0 11 3101 1101 14113001 610011 481 3701 171 531 241 811 6511811821 471138118112511611 1129 17 ...126525 ....1 2.0 II 1101 191 161 2601 240011 511 1431---1 471 15[ 411---!1 5---I---l---l--l 211 311 ---- 18 ...126508 .... 6.0 11 801 221 241 59011300011 931 2171 241 711 251 711 441 91 821 211 641 61 55S 711 725 19 ...126509 ....1 3.0 11 301 121 41 2001 800!! 541 1231---!1 451 121 311---1 31---I---I---1--1 141 211 20 ...126518 ....1 5.0 11 101 3401 91 701 60011 1961 2661---!1 691 lII 211---! LI---I---I---1--I 41 l-- 21 ...126504....1 2.5 11 401 221 51 2201 60011 401 1001---1 451 101 211---1 31------I---1--1 I01 ill ---- 22... 126505 ....1 8.0 11 2101 581 381 87011200011 2831 5451 751 2431 5511111 7811311101 261 791 81 651 811 1599 23... 126506 ....1 3.0 11 101 61 1! 501 30011 241 491---1 221 61 211--- 11 ---I---!---I--! 61 i!l ---- 24 ...126479 ....1 2.5 11 4201 561 43112001 880011 401111401---! 478112512611---1251---I---I---1--111711311 ---- 25... 126480 ....1 3.5 11 1701 11! 171 56011800011 781 1981 241 581 201 411 301 61 631 171 541 51 53! 711 617 26 ...126548 ....1 2.0 11 701 601 231 4001 210011 2101 3971---1 1481 261 611---1 51---I---I---1--1 181 211 ----

Descriptions 15...ISwarm of 1/16- to 1-in thick dikes in a 2-ft exposure. At least two similar swarms occur limmediately downhill; 500 to 1,000 cps. Located 80 ft uphill of sample 18. 16...!SamDle across 18-in pegmatitic and fine-grain dike and 18-in of chloritic schist wallrock to either I side, located 30 ft uphill of sample 18. 17... Hanging wall to sample 18; chloritic schist with several 1/4-in or less thick black aphanitic veinlets I normal to contact. 18... 16-ft thick coarse-grain pegmatite with coarse crystalline aegirine in albite, quartz, and earthy pink I mineral; some clots of . 19... 13-ft of adjacent footwall to samDle 18; similar to sample 17. 20... IFootwall chloritic schist to pegmatite; contains numerous 1/16- to 3-in veinlets and dikes striking N-S I and oriented normal to the pegmatite; 500 to 5,300 cps. Dikes include black opaques, , and I bladed pink zirconium material. 21... Hanging wall of diorite to pegmatite (sample 22) and cut by numerous sub-parallel and sub-normal black I aphanitic veinlets. 22... 18-ft thick, coarse-grain albite aegirine pegmatite with a pink earthy mineral (zircon?); 500 to 1 2,000 cps. 23... Footwall fine-grain gray diorite to sample 22, similar to sample 21. 24... 1Hanging wall of altered chloritic schist; up to 900 cps. 25... Variable grain texture and pegmatitic dike; 400 cps. 26... IFootwall chloritic schist to sample 25; 200 to 700 cps.

14 Table 4. - Pegmatite dikes and wAllrock sample results, In ppm - Continued

1 [11 1 1I 1G LIGHT REE (Cerium Subqroup)IHEAVY REE (Yttrium Subgroup Map I lWidthll I I[1I 1[ II1 1 1 IlotaiI No. IField No.1 (ft)!I Cb I Th I U I Y I Zr 11 La I Ce I PrI Nd I SmI Eu!! GdITb[ DAy Ho! ErITm I Yb! Lull REE 27 126425.... Grab.1 1 4 201240 1 1801 4581---1 1261 451 1011 ---1201 --- 1---11341 1711 ---- 28. .126517 ....1 8.0 11 1601 451 351 65011500011 1511 3621---l 1241 341 711---1 91---1---I1------1 8Z1 1111 ---- 31.:.126482 ....1 0.7 11 2601 451 13112001 990011 1681 5071---1 2081 591 1411---1181---I---I---I---11251 1811 ---- 32 ...126483 ....1 2.0 11 101 281 41 801 20011 551 1151---1 301 61 211---I 11---I--- 1-1----I1 41 111 33 .. 126484 .... 2.0 112401 9611600119000113801 5171123011401 4061 891 1 921 8111091241161 391 51 841 10112779 34 ...126549 ....1 2.5 11 3201 1101 49115001 810011 5121118011301 39011011 211114212511941 4211221 141 921 1111 2976 35... 126550 ....1 2.5 11 4901 231 211330011400011 2271 45213201 2391 581 13114071151499110612791 34! 401 511 2694 36... 126485 ....1 2.7 11 5801 5111171 70012000011 4131 8061---1 3301 521 911---! 81---I---I---1---1 601 911 ---- 39... 125219 ....1 1.5 11 LI 6101 891 4001 210011 7131 9561---1 2741 371 611---1 41---1---1---1---1 181 311 ---- 42... 126551 ....1 3.0 11 2001 131 71 5501 540011 1401 3151 371 1521 321 811 511101 901 231 711 81 631 811 1008 43... 126487 ....CR...I! 1201 121 51 3701 290011 741 2821---1 721 201 '511---1 61------1---I1 401 511 ---- 44 ...126423 ....1 2.0 11 2901 321 511140012700011 101 2711 51 201 91 311 3011111701 5512111 3312301 3011 1088 45... 126463 ....I 1.0 11 2501 231 211 3501 520011 251 931---1 221 61 111---1 41------1---i---1 431 611 ---- 47... 126619 ....110.0 11 1301 26011581140017500011 311 2281---1 761 181 611---1161---I---I---I---11981 3311 ---- 48... 126651 ....1 6.7 1112001 1801240124001 550011 552111201---1 50711311 2911---1361---I---I---I---11211 1711 ---- 50... 1266181.... 3.0 11 LI 3001 L110001 540011 400110001---1 4001 LI L111001--14001 LI L17001 LI ---11 ---- 51... 1262571... CR 11 LI 2001 L1250010.3611 500114001---1 8001 LI L114001--15001 L1300120012001 --- I- 52... 126327 ... 1 1.2 11 3001 8001200149001 ---1122001560018001280016001100118001 190012001500190013001 L'115900 L Less than detection limits. --- Not analyzed.

Descriptions 27...lPegmatite rubble of albite, quartz, actinolite, amphibole, pink earthy mineral, and opaques; 1 500 to 900 cps. 28... ISimilar to sample 27. 31... Combined sample of 4-in radioactive dike and wallrock. 32... IChloritized schist footwall to sample 34; 400 to 800 cps. 33... !Chloritized schist hanging wall to sample 34; 200 to 2,000 cps. 34... lBanded dike, with pegmatite; varies in width to 4 ft; 900 to 2,500 cps. 35... Banded dike composed of quartz, albite, ribbons of aegirine, euhedral riebeckite and zircon, and I earthy clots of zircon; to up 2,400 cps. 36... Banded coarse zircon crystals and clots in fine-grain silica-rich matrix. 39... IComplex pegmatite, one of several pegmatite lenses that occur along margin of syenite intrusion; I 1,000 to 1,500 cps. 42... Coarse-grain riebeckite and syenite pegmatite dike; 200 to 800 cps. 43... Random chips of pegmatite and Fe-stained syenite rubble in 20- by 50-ft size area; 200 to 400 cps. 44... Coarse-grain syenite pegmatite with masses of zircon and euhedral riebeckite and aegirine; 200 cps. 45... ICoarse-grain Mn-stained syenite pegmatite. 47... lCoarse-grained manganese stained pegmatite with bordering finer-grained bands, outcrop poorly exposed; I 500cps. 48... Manganese-stained float boulder of vein 10 in or more wide, found in alluvial fan of small creek on South Arm; 900 cps. 50...1200 lb bulk sample from-3-ft vein dike. Assay by ICP-MS. 51...1200 lb bulk sample of vein swarm (vein material only). Veins range 1/2-to 5-in-thick cutting I green-gray schist. Assay by ICP-MS. 52... 190 lb bulk sample of 14-in vein dike found in creek bed rubble. Assay by ICP-MS.

15 Table 5. - Eudialyte-bearing pegmatite sample results, in ppm.

[ 1- 11 I I I 1 ILIGHT REE (Cerium SubqroUpDIHEAVY REE (Yttrium Subgroup) I Map |Widthl1 I I I I IT I I 1 11 1 I I I I IlTotal No. IField No.1 (ft)II Cb I Th I U I Y I Zr 11 La I Ce I Prl Nd I SmlEull GdITbI Dyl Ho Er Tm YbILuj REE 29 ...126420 ....ICR...l112301 51 2111001 780011T 1471 5391i---1 2201 631141 _---1221 ---I--- I-- 1-1 981121 __-- 30...126455....ICR...11 2701 301 171140011100011 2401 6501 851 3081 861181114012612221 521146118112011511 2126 37...125218....I 1.0 11 L1140011811 7201 320011 7571110011301 3461 581 911 621101 781 181 431 31 361 611 2656 40...125217....ICR...11 3001 1401 371160011200011 4961 9801---1 440110612311 ---1281---1---1---1--110511211 ---- 41...125646....ICR...i1 3291 281 291150011400011 4701 9801---1 --- 114511211---1371----I--1---I--111011311 ---- I Interference. CR Random chip sample. L Less than detection limits. --- Not analyzed.

Descriptions 29...1Random chips of eudialyte syenite (?) in creek bed just below contact with metavolcanics. 30... Random chips of eudialyte nepheline dike in syenite. 37... IRadioactive pegmatite-pod in syenite containing riebeckite, plagioclase , nephelene (?), I eudialyte, quartz, and unidentified orange and yellow minerals; 2,200 cps. 40... IRandom chip of eudialyte-bearing pegmatite that forms 1- to 2-in irregular bands in syenite. Traces I of galena; up to 700 cps. 41... Random chip of eudialyte-bearing pegmatite that forms multiple 1- to 2-in thick irregular bands in I in syenite. Traces of galena; up to 700 cps. Table 6. - Other sample results, in ppm

I ii I 1 1TI ILIGHT REE (Cerium Subqroup)IHEAVY REE FYttrium Suboroup) I Map! lWidtbll I I I I IT- I I I I I I IlTotal No. IField No.1 (ft) I Cb I Th I U I Y I Zr 11 La I Ce I Pr! Nd I SmIEull GdlTbl Dy! Ho| ErlTml YbILull REE 8....126430....1 2.5 11 201 21 1T401 40011 91 281---1 121 31 211---1 Ll ------5111 - 38...125220....ICR...!I 501 111 31 1701 130011 641 1391---l 941 191 511---1 41---I---I---1--1 171 211 ---- 46...126502....ICR...11 901 151 61 2701 130011 681 1561---1 701 161 411---1 61---I---I---!--1 241 411 ---- CR Random chip sample. --- Not analyzed. L Less than detection limits. Descriptions 8.... [Carbonitite (?) with central core of Degmatitic quartz cutting hornfels metasediment. Carbonate I contains disseminated pyrite and weathers to limonite-clay; non-radioactive. 38... Random chips of unaltered syenite, no eudialyte present; 170 cps. 46...|Aphanitic green rock with angular patches and clasts of fine-grain magnetic black material; non- I radioactive. Exposed for 50 ft along logging road. apparently increases with distance from the intrusion. An avalanche gully at sample locations 6-11 demonstrates the multiple nature of the dikes. At least four, and likely more, dikes are present between the lake level and 250 ft elevation, and additional vein-dike float was found above that level. At some sample sites, mineralization was also found in the chloritic wallrock (e.g. sample nos. 24 and 33). Analytical data (table 4) clearly indicates that REE, columbium, and silica content, and to a lesser degree , manganese, and , increase with the distance away from the intrusion. This elemental zoning indicates mineralization is associated with the more highly evolved, quartz-rich, hydrothermally altered vein-dikes and particularly the distal veins. Figures 2 (inset) and 5 display the correlation of increasing total REE + yttrium values to the increasing amount of silica in the samples. The data indicates that the deposition of higher concentrations of lithophile elements, normally associated with a late-stage volatile-rich intrusive phase, occurs at distance from the Dora Bay intrusive source. Likely a late-stage hydrothermal phase of the Dora Bay intrusive complex was introduced along and controlled by a north-south fault or fracture zone at least partially aligned with bedding. The ultimate southward limit of the volatile precipitation and mineralization could not be determined due to extensive surficial cover including cemented glacial till. Similarly, if the same processes have taken place to the north of the intrusion, they could be projected to occur in the heavily forested slopes east of the bay head. Due to the reconnaissance nature of the sampling, no available drill data, and the association of dikes with recessive topography, it was not possible to accurately determine the average grade of mineralization. Vein-dikes and the distal veins they evolved into, contain concentrations of REE, yttrium, and columbium. The total of yttrium and REE in many of the samples approaches or exceeds 0.4 pct, which is equivalent to approximately 0.5 pct REO (rare-earth and yttrium oxide, as it is commercially traded). Grades range from 1,000 to 4,600 ppm Y, 1,000 to 15,900 ppm REE, 120 to 1300 ppm Cb, low to 7.5 pct Zr, and traces of , beryllium, and tantalum. These values represent only the mineralized vein-dikes and veins for which widths range from 0.1 to 3.0 ft and does not include wallrock dilution necessary in mining or the weakly mineralized coarse-grained pegmatites. It is further noted that ICP-MS analyses of the larger samples for metallurgical testing (50-52) are significantly higher than the chip sample results which were performed by neutron activation. This may suggest REE self-shielding during activation which results in incomplete detection. About 1,500 ft north of pan sample location 11, near the northern map border of figure 4, mineralized vein float (sample 48, table 4) from an 0.67 ft wide vein was found in the fan of a small creek. Source of the mineralized rock was not located, however the occurrence suggests additional dike(s) may be found near the South Arm of Cholmondeley Sound. A few boulders of peralkaline granite were also found nearby.

18 80 I

78

76 O0

7 4-

7 2

70 0 / KEYo 0 68

cam66/ _ ~~~~~~~~~~~~~~~AEudiallyte syenite 0 0 64 _*@ / Pegmatitic dike

62 I/ 0< Vein-dike

60 -A + Vein

58 -

50 .05 .10 .20 .30 .40 .50 .60 .70 .80 .90 1.0 1.1 1.2 REE + Y (pct) Figure 5. - Correlation of REE+Y to SiO2 in mineralized pegmatite dikes. RESOURCES

Classification of resource estimates in this report fall under the category of inferred subeconomic and hypothetical resources. The range of grade of the mineralized bodies is below that of producing REE deposits elsewhere in the world (3). Furthermore, metallurgical recovery of the valuable minerals at present has not been demonstrated. Inferred resource estimates are based on assumed continuity beyond the sampled locations for where there is geologic evidence. Hypothetical resources refer to the presumed existence of additional parallel mineralized vein-dikes and veins not exposed in either outcrop or rubble. Resource estimates are based on a tonnage factor of 10 cubic ft per St. Resource grade given below is tentative and based wholly on an arithmetic mean of available analyses from random sample sites (table 4). Resource tonnage estimates are made on two areas of the dikes shown on figure 2. The first area (North Dora Lake) is represented by sample nos. 32-36, where a vein-dike having a thickness of at least 3 ft is inferred to extend eastward and outcrop at or near the 1,000 ft elevation. By calculating the intervening volume of the vein-dike, a total of 0.5 X 106 st is inferred. Sample values (no. 33-36, 50) average:

Cb 442 ppm U 71 ppm Y 1775 ppm Zr 1.53% REE 2816 ppm

Sample 47 suggests this zone may extend further to the north of the area for which resources are calculated. The second area (South Dora Lake) is predicated on sample nos. 1-16 and 51-52 and estimates include inferred and hypothetical tonnage along a projected strike of 4,000 ft and an assumed depth along dip of 2,000 ft. Field observations of rubble and outcrop indicate that there are a multiple of subparallel bodies present along the 4,000 ft of strike. Tonnage estimates assume an aggregated thickness of mineralized dikes ranging from a minimum of 1.5 ft to a maximum of 10 ft. By these criteria, a resource of between 1.2 X 106 and 8.0 X 106 St is estimated, of this, 2.4 X 106 St is considered inferred. Average sample values are:

Cb 340 ppm U 27 ppm Y 1969 ppm Zr 1.08 pct REE 3647 ppm

HEAVY MINERAL SURVEY

Panned heavy mineral concentrates were collected to evaluate the possible existence of additional mineralized bodies in the region near Dora Bay and South Arm Cholmondeley Sound (table 7). Pan data, appendix B, shows a strong presence of sodium, which is indicative of the Na-rich and derived from the Dora Bay intrusive complex. The data suggest the complex extends under surficial cover and bedrock to the west.

20 TABLE 7. - Volumes and weights of heavy nrineral concentrates, and normalized yttrium in panned samples from the Dora Bay area

1(-3/8 in)l lAnalysesIRecovered I 1 1(-3/8 in)l lAnalysesiRecovered | I Sample IConcentratelYttrium I Yttrium I I I Sample IConcentratelYttrium I Yttrium Map No.lField No.1 Vol. ft3I Wt. g. I opm I mg/pan 1/ IMap No.jField No.1 Vol. ft3I Wt. g. I ppm I mg/pan

1. 26547 ....1 0.17 1 152.8 1 25 1 3.82 120 . 26523 ....1 0.17 1 96.1 F 31 T 2.98 2...... 126546....! 0.17 1 56.6 1 26 1 1.47 121 . 126457 .... 1 0.17 1 46.6 1 47 1 2.19 3 . 126544 .... 1 0.17 1 58.2 1 25 1 1.45 122 . 126456 ....1 0.17 1 50.9 1 260 1 13.23 4 . 126516 .... 1 0.25 1 114.3 1 33 1 2.56 123 . 126454 .... 1 0.17 1 24.2 1 240 1 5.81 5. 126515 .... 1 0.17 1 119.4 1 23 1 2.70 124 . 126543 .... 1 0.17 1 213.1 1 180 1 38.36 6 . 126513 .... 1 0.17 1 102.8 1 32 1 3.29 125 . 126452 .... 1 0.17 1 71.9 1 230 1 16.54 7. 126477 .... 0.11 1 31.1 1 36 1 1.73 126.....126419....! 0.17 1 117.2 1 190 1 22.27 8 . 126474 ....I 0.11 1 39.8 1 32 1 1.96 127 . 125481 .... 1 0.17 1 94.2 1 54 1 5.09 9 . 126473 .... 0.11 1 34.1 1 38 1 2.0 128. 125486 .... 1 0.17 1 132.5 1 64 1 8.48 10 . 126471 .... 0.11 1 93.9 1 250 1 36.3 129 . 125460 .... 1 0.17 1 108.7 1 250 1 27.17 11.....126472....! 0.15 1 87.0 1 20 1 1.97 130 . 125462 ....1 0.15 1 36.3 1 520 1 21.40 12 . 126464 .... 0.11 1 58.1 1 72 1 6.4 131 . 125461 ....1 0.17 1 41.9 1 980 1 41.06 13 . 126459 ....1 0.17 1 96.2 1 160 1 15.39 132 . 125424... 1 0.17 1 58.7 1 78 1 4.58 14 . 126466 ....1 0.17 1 75.0 I 260 1 19.5 133 . 125422....! 0.13 1 55.6 1 33 1 2.39 15 . 126503 ....1 0.1.7 1 91.6 1 390 1 35.68 134 . 125469 ....1 0.17 1 107.5 1 35 1 3.76 16.....126501....! 0.17 1 93.4 1 770 1 71.92 135 . 125512 ....1 0.17 1 34.8 1 40 1 1.39 17 . 126467 ....1 0.17 1 210.8 1 270 1 56.92 136 . 125511 ....1 0.17 1 40.8 1 41 1 1.67 18.....126526....! 0.17 1 167.4 1 44 1 7.37 137 . 126328 ....1 0.56 1 216.2 1 98 I 21.17 19.....126524.... 1 0.17 1 102.8 1 30 1 3.08 1 1 l 1 l l

1/Recovered Y in mg/pan is determined as (.001)(Analysis Y, ppm)tconc. wt. in grams) (no. of 14 in. pans of -3/8 in. sample) Analytical results for other elements given to appendix B. Visual examination of the rock sample data set found yttrium to be present in all mineralized samples. Therefore, yttrium was selected as a pathfinder element in the panned heavy mineral date. Analytical values in ppm Y are normalized with respect to the actual weight of recovered heavy mineral concentrate in grams from one 14 in diameter pan of fine gravel and sand. This procedure calculates the recovered elemental yttrium (in mg) in each par at each sample site. Date in table 7 indicates possible mineralized sources of yttrium, and therefore, REE and cclumtium occurrences, are located in the north-south trending valley immediately west of the mapped Dora Bay syenite/granite body shown on figure 2. Creek rubble at map location 17 (fig. 4) was noted to include aegirine syenite. The singular anomalous value at location IC correlates with the reported anomalous yttrium and beryllium stream sediments by Herreid and others (5). DISCUSSION AND CONCLUSIONS The pegmatite dikes at Dora Bay, including vein-cikes and distal veins, contain concentrations of REE, yttrium, zirconium, and minor amounts of columbium. Significant values are concentrated in the vein-dikes and particularly in the more siliceous veins. Estimates of inferred and hypothetical tonnage range from 1.7 X 106 to 8.5 X 106 st for two deposits. Samples of the vein-dikes and veins commonly contain on the order of 4,000 ppm combined REE and yttrium, which is equivalent to approximately 0.5 pct PEO (including yttrium). Actual REE and yttrium values may be higher than indicated due to self-shielding effects during neutron activation analyses as evidenced by assays of several bulk samples. Cclumbium values generally do not exceed several hundred ppm. Compared to the deposits located at nearby Bokan Mountain (1,2), the Dora Bay dikes contain lower REE, yttrium, and zirconium values, although a higher percentage of the total REE value is contained in the heavy yttrium subgroup (fig. 6). Dora Bay occurrences contain markedly lower columbium than Bokan Mountain. In addition, unlike the Bokan Mountain deposits, there is little potential for by-product tantalum, tin, beryllium, gold, uranium, and other metals, although minor levels were detected in several Dora Bay samples, particularly the veins. There is a pronounced zonation of the lithophile metal values in vein-dikes and veins distal to the Dora Bay alkaline complex. REE+Y values are shown to correlate positively to the degree of hydrothermal alteration as demonstrated by the increasing content of silica. This therefore suggests the incomparable lithophile elements were partioned in very late stage magmatic fluids that excaped the intrusive complex into pre-existing north-south fracture zones. This zonation also suggests that higher grade REE and yttrium deposits, perhaps with base metals and precious metal credits, may exist along parallel striking structures or beyond the area investigated. Future exploration should initially be concentrated at a distance of several hundred- to several thousand-feet from the intrusion. The regional favorability for additional deposits is further reinforced by the anomalous yttrium heavy mineral values found in creek beds with syenite gravel 1 mi west of Dora Lakes, and the discovery of mineralized vein-dike float on the South Arm of Cholmondeley Sound.

22 100 I I I I I I I

Light Rare-Earth Oxides,Cerium Subgroup i Heavy Rare-Earth Oxides,Yttrium Subgroup 50.0 - 40.0 - I

30.0 /

20.0 I I KEY -.-+ -.+ California bastnasite ore (1) 20.0 >/ \ II

E 0 I I Florida monazite placers (1)

10.0 , \ / V I I - Bokan Mountain (polymineralic)

bo\\ \ // /s \ \ I I __ Dora Bay (polymineralic) Q. 4 0 \\ // I I datad source Hedrick, 1985 C9) WJ 5.0 \,

3.060,0 A\

I \ /'r 0 DO C / a0)2.0 / I

0~ w0 1.0 US R

0~~~~~~~ 0'11

-~~~~~~~~~~~~~~~~~~~~~~~~~~~ 0.5 hI

0.3 II /I

0.2~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 0

Yb O LU 0 Y 0 La2O3 CeO 2 Proll Nd2O 3 SM20 3 Eu2O3 Gd 2O3 Tb4O7 Dy203 Ho2O3 Er2O03 TM 203 2 3 2 3 2 3

Figure 6. - Comparision of REE composition of Dora Bay pegmatite dikes to mineral deposits at Bokan Mountain and other major U.S. REE sources. Based on the above conclusions, it should be noted that mineralized dikes evolved from the Dora Bay complex show a preferred alignment to the trace of a regional north-south fault as previously mapped (6). Subsequent erosion has reduced the area of the fault zone to the point that much of the area suspect for containing mineralized bodies now lies under glacial till, fresh water lakes, and seawater. Also on the South Arm, and approximately four miles to the northwest of the head of Dora Bay, Herreid and others have described the Friendship Lode copper deposit occurring in chloritized and silicified Wales Group schist (5). The area is the loci of numerous alkaline basaltic dikes. Their samples from the veins showed anomalous levels of bismuth and yttrium (up to 300 ppm Y), and yttrium and beryllium were also anomalous in stream sediment samples from the immediate area to either side of the South Arm. It was suggested, therefore, that a buried intrusion with similarities to Bokan Mountain may exist at depth in the area (5). By analogy, the REE+Y zonation pattern at Dora Bay indicates future exploration of the Friendship Lode should examine the possibility of REE deposits lateral to or at depth, particularly along zones of structural weakness. Interpretation of aerial magnetic data (7) suggests several other syenitic to dioritic bodies may occur near Dora Bay along a poorly defined regional trend that includes most REE occurrences on southern Prince of Wales Island. The likelihood of similar zoned REE+Y-bearing dikes occurring above and lateral to those buried complexes, and particularly along structural linears radiating from them, should be evaluated.

24 REFERENCES

1. Warner, J. D. and J. C. Barker. Columbium- and Rare-Earth- Element-Bearing deposits at Bokan Mountain, Southeast Alaska, IC (in progress).

2. Barker, J. C. and C. L. Mardock. Lithophile Element Deposits, REE-Y-Nb, On Southern Prince of Wales Island, Alaska. Presentation at Process Mineralogy, AIME-TMS Annual Conf. Jan. 1988, Phoenix, AZ. Proceedings in preparation.

3. Cunningham, L. D. Columbium. Ch. in Mineral Facts and Problems, 1985. pp. 185-196.

4. Anstett, T. F. Availability of Rare-Earth, Yttrium, and Related Oxides - Market Economy Countries. BuMines IC 9111, 19 pp., 1986.

5. Herreid, G., T. K. Bundtzen, and D. L. Turner. Geology and Geochemistry of the Craig A-2 Quadrangle and Vicinity, Prince of Wales Island, Southeast Alaska. AK Div. of Geol. and Geophys. Surv., Geol. Rep. 48, 1978.

6. Eberlein, G. D., M. Churkin, Jr., C. Carter, H. C. Berg, and A.T. Ovenshine. Geology of the Craig Quadrangle. U.S. Geol. Surv. Open File Report 83-91, 1983, 27 pp., 4 plates.

7. Aeromagnetic map of the Craig Area, Alaska. U.S. Geol. Surv. Open File Report 84-166, 1984, 3 plates, 1:250,000 scale.

8. , 2nd edition, R. L. Bates and J. A. Jackson, eds., 1980. American Geol. Institute, Falls Church, VA.

9. Hedrick, J. B. Rare Earth Elements and Yttrium. Ch. in Mineral Facts and Problems. U.S. BuMines 1985, pp. 647-664.

25 APPENDIX A

Rock sample multi-elements analyses

26 ROCK SAMPLES

ElementlUnits! 1 I 2 I 3 I 4 I 5 I 6 SiC2 1 % 1 77.5 1 79.5 1 78.7 1 60.9 1 76.6 1 73.5 A1203 % I 5.321 5.031 8.301 12.3 I 6.811 7.05 CaO %X 3.111 0.631 1.691 3.701 2.801 1.40 MgO % I 0.691 0.701 0.761 1.831 0.451 0.43 Na2O % 2.041 2.73! 3.571 5.051 2.911 3.26 K20 %Z 1.621 0.821 1.741 1.821 1.581 1.27 Fe203 % I 2.491 1.941 1.781 8.111 3.791 6.10 MnO % I 2.881 2.071 0.211 0.481 0.281 0.18 TiO2 % I 0.251 0.301 0.241 0.921 0.371 0.34 P205 % 0.081 0.051 0.101 0.371 0.191 0.10 LOI % I 1.771 1.461 1.161 3.691 2.461 2.15 SUM % 99.101 96.701 99.301 100.0 I 100.0 I 99.50

Ag I ppm I <0.5 I <0.5 ! <0.5 I <0.5 I <0.5 I <0.5 As ppm! <2 18! 4 16 23 22 Au !ppb <10 <20 1 19 1 <15 <20 17 B fppm! 80 100 1 80 1 60 60 30 Ba !ppm! 540 2200 370 240 270 150 Be !ppm! 42 94 51 26 39 21 Br oppm <2 <4! 2! <1 I <1! 2 Cd I pom! 2.0 2.0 1.0 <1.0 <1.0 2.0 Co !ppm! 4! 8 <3 15! 4! 3 Cr !ppm 10 20 10 10 30 10 Cs I ppm I <0.9 I 1.7 <(2.0 j 1.9 I <1.4 <(1.4 Cu !ppm 6.0! 26 4.0 8.0! 13 6.0 Ge !ppm! <10 <10 <10 20 <10 <10 Hf ppm! 65 46 23 46 140 420 Mn I ppm I 20000 I 15000 1 1400 I 3200 I 1700 I 750 Mo ppm< <5 <5 I <5 I <5 I <5 <5 Nb ppm! 620 1300 400 410 390 190 Ni !ppm! 20 18 10 1 10 12! 6 Pb ppm! 48 72 14 54 24 52 Rb ppm! 80 90 130 220 110 70 Sb I ppm I 3.4 | 2.3 | 0.7 I 2.7 | 1.6 I 0.8 Sc I ppm I 3.9 I 3.4 I 3.3 I 16.9 I 6.1 0.8 Se ppm 27 43 <5 36 <5 <5 Sr ppm! 190 40 260 70 20 <10 Ta ppm! 40 33 17 I 28 29 12 Th !ppm! 230 97 | 110 250 300 54 U I ppm! 22.4 76.6 17.7 46.9 42.0 19.6 V ppm! 26 44 22 160 64 22 W ppm! <3 <3 <3 <4 <4 <3 Y I ppm I 3600 I 3300 I 4600 I 2200 I 2700 i 1600 Zn !ppm 1700 2200 190 1200 360 170 Zr I ppm I 4900 I 4600 I 2300 I 3400 I 9900 I 25000 La ppm 581 1510 374 479 712 179 Ce ppm 1440 3090 958 1000 1380 537 Nd ppm! 929 1330 378 408 590 200 Sm ppm! 284 315 129 108 151 58.0 Eu I ppm! 71.1 72.0 30.8 25.7 34.8 13.3 Tb I ppm! 76.6 60.2 50.8 39.5! 43.7 20.3 Yb |ppm 155 125 167 130 168 188 Lu I ppm] 16.6 14.5 I 17.2 13.3 20.7 28.3

27 ROCK SAMPLES

ElementlUnitsl 7 1 8 1 9 1 10 I 11 I 12 SiO2 I % 1 68.5 1 39.6 1 79.0 1 69.1 1 76.5 1 75.7 A1203 I % 1 6.891 14.0 ! 6.481 6.711 7.211 7.78 CaO I % 1 2.161 13.1 1 1.361 2.401 0.871 0.38 MgO I % 1 0.211 2.291 0.391 0.381 0.211 0.48 Na2O X 1 2.841 2.821 2.971 4.841 3.381 4.53 K20 I % 1 3.201 2.391 3.341 1.931 1.431 2.82 Fe203 I % i 8.001 8.981 4.491 9.871 5.801 4.91 MnO I % 1 0.231 0.161 0.281 0.311 0.121 0.21 TiO2 I % 1 0.321 1.311 0.181 0.141 0.161 0.19 P205 I % 1 0.261 0.31! 0.211 0.541 0.191 0.15 LOI I % 1 2.311 14.9 1 0.621 0.921 1.161 0.61 SUM I % 1 99.201 100.0 1 100.2 1 100.0 1 100.2 1 99.70 1 1 1 I 1 1 1 Ag I ppm I <0.5 <(0.5 I <0.5 <0.5 <0.5 <0.5 As !ppm 8 130! 2! 8! 4! 2 Au |ppb 31 | <6 18! <20! <10 <10 B ppm! 40 60 40 20 ! 40 30 Ba ppm! 350 220 410 170 180 580 Be Ippm 19! 4 19 18 16 17 Br !ppm! 3! 3 <1 <(2 <(1 I 2 Cd ppm 3.0 <1.0 2.0 2.0 1.0! <1.0 Co !ppm! 4 46! 4! <4 4! 2 Cr ppm! 10 160 10 20 20 ! 10 Cs I ppm <1.5< ! 1.4 I 1.9 <(2.0 I 1.5 I 1.0 Cu ! vpm ! 6.5 I 56 ! 15 ! 2.5 I 3.5 ! 3.5 Ge Ippm! 20! <10! <10 10 ! <10 10 Hf Ippm 610 10 ! 75 330 340 190 Mn ! ppm ! 1100 I 1100 1 2000 1 1700 1 280 1 1200 Mo ppm <5 <5< <5< <5< <5 I <5 Nb |ppm 130 20 I 140 270 120 150 Ni Ippm! 9 81! 8 13! 9! 4 Pb ppm 86 <(2 | 12 | 150 | 120 1 24 Rb !ppm 210 50 220 90 | 100 230 Sb I ppm I 0.6 | 3.4 I 0.2 | 0.4 | 1.0 | 0.5 Sc I ppm I 3.4 I 36.6 I 2.8 I 0.9 ! 0.9 I 2.7 Se !ppm <5 <5 <5 I <5 I 20 ! 25 Sr ppm <10 180! <10 150! <10 10 Ta ppm! 8! <(1 9 25! 9 13 Th !ppm| 39 2.0 240 320 I 100 110 U I ppm ! 24.5 ! 1.0 ! 16.4 I 36.4 I 20.4 ! 23.2 V ppm! 40 270 28 18 20 16 W !ppm! 8! 4! 4! <3! 3! <3 Y ppm 1400 40 1000 2100 2200 1900 Zn ppm 380 87 620 330 110 320 Zr I ppm I 30000 ! 390 I 4600 ! 18000 I 21000 ! 12000 La ! ppm 1 186 ! 9.3 ! 193 I 552 ! 163 I 191 Ce Ippml 578 28 519 1290 539 583 Nd ppm! 224 12 | 245 | 644 | 185 | 224 Sm ! ppm I 44.4 I 3.2 I 58.8 I 141 ! 51.0 ! 59.1 Eu !ppm 9.7 1.8 13.8 35.8 12.7 14.0 Tb ! pom | 15.7 <(0.5 | 15.6 | 40.8 | 24.6 I 20.0 Yb I ppm ! 223 | 5.1 | 82.6 | 249 | 226 | 180 Lu ppmI 1 34.3 I 0.721 11.3 1 36.2 1 33.0 1 24.1

28 ROCK SAMPLES

ElementlUnitsl 13 1 14 1 15 1 16 1 17 I 18 SiO2 1 Z 76.0 1 69.0 1 76.1 1 69.0 [ 65.01 62.2 A1203 I % 1 7.731 8.761 7.231 8.941 15.2 1 13.7 CaO I % 1 0.741 1.241 0.511 2.811 1.111 0.57 MgO I % 1 1.281 1.681 0.331 1.231 1.611 0.13 Na2O X 1 4.761 3.511 5.121 5.281 5.401 8.35 K20 I % 1 1.571 2.931 2.391 2.511 4.221 3.45 Fe203 I % I 5.201 7.001 4.251 7.561 5.391 8.10 MnO I % 1 0.261 0.251 0.521 0.341 0.221 0.25 TiO2 I X 1 0.291 0.571 0.161 0.431 0.451 0.34 P205 I % I 0.141 0.161 0.111 0.131 0.09! 0.04 LOI I % I 1.001 2.001 1.081 0.931 1.311 0.92 SUM I X I 100.1 1 99.501 99.401 100.3 1 100.5 1 99.90 1 1 I 1 I I 1 Ag I ppm <0.5 <0.5 <0.5 <0.5! <0.5! <0.5 As !ppm! 2! 9! 31 10 I 31 I 2 Au |ppb <10 640! <14 13! <7 <9 B ppm! 40 30 30 30 401 20 Ba ppm 660 260 440 480 730 1 170 Be ppm! 14 46 18 17 I 12! 9 Br ppm 1 1 I <1 2 I 2 <1 Cd I ppm | <1.0 | <1.0 <(1.0 <(1.0 <(1.0 <(1.0 Co Ippm! 4! 6! 3! 4! 5! 3 Cr ppm! 10 20 ! 10! <10 10! <10 Cs !ppm <1.7 1.9 2.2 1.4 2.0 <1.4 Cu I ppm I 7.0 I 3.5 I 3.0 ! 11 I 12 I 1.5 Ge !ppm! <10! <10 20 <10 30 20 Hf Ippm! 94 300 150 110 39 240 Mn I ppm I 1600 I 1400 I 3600 I 2100 I 1300 I 1500 Mo ppm <5 < 5 <5 < 5 <5 I <5 Nb ppm 310 130 570 310 110 80 Ni !ppm! 4! 8! 9 7 I 11! 2 Pb ppm! 20 32 44 30 24 78 Rb !ppm 100 320 170 130 130 270 Sb I ppm I 0.3 | 1.0 | 0.4 I 1.0 I 0.3 | 0.3 Sc I ppm 1 4.5 I 8.0 I 1.4 I 7.1 I 14.2 I 1.7 Se !ppm! 24! <5 23 35! <5 <5 Sr Ippm <10 <10 10 20 20 30 Ta !ppml 12 11 36 21 I 5! 6 Th Ippml 36 86 160 110 19 22 U I ppm I 17.6 I 30.8 I 30.2 I 14.5 I 15.8 I 23.5 V ppm! 24 58 12 38 68! 6 W Ippm! <3! 5I 7! 5 <3 <3 Y ppm 1200 1200 1200 1300 260 590 Zn lppm 330 370 450 250 190 350 Zr I ppm 1 6000 I 16000 I 9400 I 6100 I 2400 I 13000 La Ippm I 208 I 105 I 537 I 48.2 I 51.3 I 92.9 Ce !ppm 591 395 1470 1 370 143 217 Nd oppm1 260 97 | 518 53 47 I 71 Sm I ppm 1 71.8 I 32.8 I 105 I 23.8 I 15.1 I 25.3 Eu I ppm I 17.9 I 8.5 I 23.6 I 8.2 I 3.8 I 6.7 Tb | ppm I 19.8 I 15.0 | 25.7 | 17.9 | 4.7 I 9.4 Yb Ippmi 89.8 137 113 125 21.2 55.3 Lu I ppm 11.7 I 19.31 14.9 16.1 I 2.801 7.07

29 ROCK SAMPLES

ElementlUnitsl 19 I 20 I 21 I 22 I 23 I 24 SiO2 I% 1 70.3 64.3 64.2 62.3 63.6 62.6 A1203 %X 13.1 I 13.5 I 13.9 I 15.0 I 13.0 I 13.5 CaO % I 0.231 0.681 1.201 0.691 2.511 1.07 MgO % 1.061 1.191 1.441 0.211 1.341 0.38 Na2O % I 4.611 9.631 8.501 7.531 4.661 8.79 K20 % I 3.881 1.981 2.731 3.671 6.101 2.82 Fe2O3 % I 4.001 6.231 6.061 6.661 6.061 7.47 MnO % I 0.101 0.341 0.231 0.331 0.251 0.26 TiO2 % I 0.351 1.321 0.631 0.371 0.591 0.45 P20s5 l % 0.071 0.321 0.171 0.09! 0.131 0.05 LOI % I 1.081 0.541 0.851 1.541 0.691 1.46 SUM I % 99.001 100.2 I 100.1 I 100.2 I 99.101 100.3

Ag I ppm I <0.5 I <0.5 <(0.5 <(0.5 <(0.5 <(0.5 As !ppm! 7 57 16 10 I 20 1 <2 Au !ppbl <6 <9 141 <11 I 40 <10 B ppm! 40 30 30 30 30 20 Ba ppm 900 240 410 300 630 290 Be !ppml 7 ! 39 I 15 I 22 I 10 I 15 Br !ppm! 2 I <1 1 ! <1 I 1 I <1 Cd I ppm I <1.0 I <1.0 I <1.0 | 1.0 I <1.0 <1.0 Co ppm! 3! 4! 5! 4! 4! 2 Cr !ppm! <10 10 <10 <10 <10 10 Cs !ppm 1.1 <1.6 1.8 2.3 2.3 <1.2 Cu ppm 4.5 2.0 3.0 2.0 6.5 1.5 Ge !ppm <10 <10 <10 <10 20 <10 Hf !ppm! 18 12 11 190! 8 140 Mn I ppm I 650 I 2200 I 1700 I 2100 I 1900 I 1700 Mo ppm! 6 <5 10 <5 <5 <5 Nb ppm! 30 10 40 210 10 420 Ni ppm! 2! 2! 3! 6! 5! 7 Pb !ppm! 12 24 24 120 16 240 Rb !ppm 110 110 140 230 210 190 Sb I ppm I 0.2 I 0.2 | 0.3 | 0.5 | 0.2 | 0.4 Sc I ppm I 8.1 I 12.8 ! 13.7 I 2.7 I 13.6 I 5.3 Se !ppm! <5 <5 <5! <10 <5 <5 Sr ppm! 20 50 10 80 10 50 Ta ppm <1 I <2 I <1 I 10 ! <1 I 23 Th ppm! 12 340 22 58 6.2! 56 U I ppm I 3.8 I 8.8 I 4.9 I 38.2 I 1.1 I 43.1 V !ppml 12 30 34 14 28 18 W Ippm< <3 <3 <3 <3 <3 <3 Y !ppm 200 70 220 870 50 1200 Zn !ppm 150 570 230 730 110 830 Zr !ppml 790 650 590 112000 330 8800 La I ppm 53.9 196 I 40.3 283 I 23.7 401 Ce !ppm 123 266 100 I 545 I 49 I 1140 Nd Ippml 45 69 45 243 22 478 Sm I ppm I 11.8 I 11.1 I 10.0 I 55.4 I 5.9 I 125 Eu Ippm 3.4 2.3 2.2 11.2 1.7 26.2 Tb I ppm 2.9 <0.9 2.7 12.6 0.7 25.4 Yb I ppm I 13.9 I 4.3 | 10.1 | 64.6 I 5.6 | 117 Lu I ppm I 1.981 0.951 1.451 8.281 0.891 13.1

30 ROCK SAMPLES

ElementlUnitsl 25 1 26 1 27 1 28 1 29 1 30 SiO2 1 % l 64.1 7 65.1 1 61.7 I 62.1 I 58.7 I 60.2 A1203 % i 14.2 13.3 I 12.9 12.9 I 15.6 I 15.0 CaO I % 1 0.291 1.611 0.271 0.231 1.471 1.32 MgO I % 1 0.031 1.191 0.031 0.071 0.031 0.08 Na2O I % 1 9.661 6.781 7.331 8.391 8.161 8.15 K20 I % 1 0.761 4.721 4.271 3.791 3.641 3.85 Fe203 I % 1 7.231 5.101 8.291 8.731 8.141 7.03 MnO I % 1 0.151 0.211 0.171 0.151 0.281 0.26 TiO 2 I % 1 0.221 0.621 0.371 0.291 0.201 0.23 P205 I % I 0.031 0.19! 0.071 0.031 0.031 0.06 LOI I % I 1.231 0.851 0.611 0.921 1.541 1.38 SUM %X 100.4 1 100.1 I 99.501 99.801 99.101 99.40 I I ! I 1 Ag I ppm I <0.5 1 <0.5 1 <0.5 1 <0.5 1 <0.5 1 <0.5 As !ppm! 6 1 2 1 12! 4 <3 1 7 Au !ppb <10 12 13 14 <10 <13 B ppm! 20 30 20 1 30 20 50 Ba tppm 170 520 1 240 250 640 420 Be !ppm! 7 19 14 20! 5 24 Br !ppm! 1 <1 ! 1! 3! 3 <4 Cd ppm <1.0 <1.0 <1.0 <1.0 1.0! 2.0 Co ppm! <2! 3! 5 1 1 ! 1 Cr ppm! 10 1 <10 10 10 <10 1 10 Cs I ppm I <1.5 I 2.8 I <1.9 I 1.2 I <1.0 I 2.3 Cu I ppm I 0.5 ! 4.5 I 1.0 I 1.0 I 1.5 I 1.5 Ge ppm! 10 <10 10 <10 <10 <10 Hf !ppm! 280 33 410 280 170 250 Mn ppm 590 1300 640 680 1800 1500 Mo ppm <5 ! <5 ! 51 I <5 | <5 I <5 Nb |ppm 170 70 250 160 230 270 Ni !pom! 3! 5! 3! 2! 4! 7 Pb !ppm! 36 68 180! 80 10 20 Rb ppm! 60 240 310 270 80 110 Sb I ppm I 0.3 ! 0.4 ! 0.9 I 0.8 | <0.2 I 0.3 Sc I ppm I 1.2 I 12.0 I 0.8 I 0.8 I 0.4 I 0.7 Se !ppm! <5 <5 I <5 I <5 ! <5 I <5 Sr ppm! 10 20 <10 <10 150 120 Ta ppm! 4! 2 14! 11 ! 17 19 Th ppm! 11 60 74 45 4.9! 30 U I ppm ! 17.3 I 23.0 ! 47.6 I 34.8 I 2.4 I 16.6 V !ppm! 10 28 12 10 10 10 W )ppml <3 <3 <3! 9 <4! 8 Y ppm 560 400 1200 650 1100 1400 Zn Ippm 310 320 450 350 200 240 Zr ! ppm I 18000 1 2100 I 24000 I 15000 I 7800 I 11000 La Ippm 77.9 210 180 151 147 240 Ce ppm! 198 397 ! 458 362 539 650 Nd Ippm! 58 148 126 124 220 ! 308 Sm I ppm 19.5 26.4 45.3 34.4 62.9 86.0 Eu Ippm I 3.6 ! 5.8 ! 9.8 I 7.2 I 14.5 ! 18.2 Tb I ppm I 6.3 | 5.2 ! 20.4 I 9.0 | 21.9 | 26.5 Yb ! ppm ! 53.1 I 17.9 | 134 I 87.2 ! 97.7 | 120 Lu I ppm 1 7.361 2.341 17.1 1 11.0 1 12.1 1 15.2

31 ROCK SAMPLES

ElementlUnitsl 31 I 32 j 33 I 34 I 35 I 36 Si02 F % 1 68.8 1 64.1 1 63.3 F 63.2 1 61.8 1 62.9 A1203 % 9.551 13.9 j 12.7 j 13.8 j 14.1 j 10.7 CaO I % I 1.861 1.861 1.041 0.611 1.511 0.96 MgO I % i 1.511 1.821 0.571 0.21! 0.231 0.16 Na2O % l 3.861 5.01Q 7.201 6.771 7.941 5.64 K20 I % 1 4.071 4.621 2.081 2.801 2.891 1.52 Fe203 % 6.67! 5.891 6.12! 7.361 5.971 10.5 MnO % i 0.291 0.211 0.421 0.411 0.471 0.30 TiO2 I % 1 0.271 0.641 0.501 0.351 0.65! 0.54 P205 I % I 0.101 0.181 0.151 0.101 0.101 0.42 LOI I % j 1.38! 2.081 2.15! 2.46! 2.16! 3.38 SUM % I 100.0 i 100.5 1 99.20! 99.501 100.3 1 99.90

Ag j ppm j <0.5 j <0.5 <(0.5 <(0.5 I <0.5 <(0.5 As ppm! 5 10! 6 <2! 2 16 Au !ppb! <10 I 10 j <14! <13 <<8 ! <10 B ppm! 30 50 I 30 20 I 30 10 Ba ppm! 800 1300 300 260 670 190 Be ppm! 16 j 30 j 55 j 37 l 23 I 14 Br jppm 1! 3 1 j 2! <1 I1 Cd ppm! 3.0! <1.0 1.0! <1.01 3.01 2.0 Co ppmj 12 12 7 i 3! 2! 3 Cr ppm! 20 <10 10 j 10 i 10 j 10 Cs ppm! 3.0! 10.5 1.6 <1.1 <1.0 <1.0 Cu j por l 5.0 j 64 i 3.5 i 7.5 I 5.5 j 3.0 Ge lppmI <10 j <10 ! <10 I <10 I 20 j <10 Hf ppmj 180! 5 340 130 53 350 Mn j ppm j 2000 j 1500 j 2900 j 2600 j 2800 j 1700 Mo ppm! <5 i <5 < <55 <5 I <5 Nb ppm! 260 10 380 320 490 580 Ni jppmj 15! 8 13! 8 12! 8 Pb jppmj 210 30 100 130 460 240 Rb ppm! 290 260 130 180 180 100 Sb i ppm i 0.3 00.3 I 2.1 | 2.3 j 0.9 I 4.4 Sc I ppm ! 9.6 j 18.9 j 4.2 j 2.3 j 1.1 1 1.8 Se ppm! 39 <5 <5 12 <5! <5 Sr ppm! 50 70 <10! <10 i 120 20 Ta ppm! 15 <1 14 11 i 3 34 Th |ppml 45 28 240 110! 23 51 U j ppm I 13.2 j 3.6 I 96.0 i 49.2 j 21.2 j 117 V jppm 72 100 34 24 24 18 W !ppmj <3 <3! 5 <4 <3 <3 Y Doppm 1200 80 1600 1500 3300 700 Zn jppmj 560 230 940 820 1600 350 Zr I ppm l 9900 I 240 j 19000 i 8100 ! 14000 j 20000 La ppm! 168 54.8 517 512 227 I 413 Ce ppmj 507 I 115 ! 1230 j 1180 I 452 I 806 Nd iPPmi 208 30 406 390 239 330 Sm j ppm j 59.0 5.7 89.0! 101 i 58.0! 52.1 Eu i ppm ! 14.4 j 1.8 1 17.0 I 20.7 j 13.2 j 9.4 Tb j ppm i 17.7 j 0.9 i 23.7 j 24.8 j 14.8 j 8.1 Yb i ppm i 125 | 4.0 j 83.7 j 91.7 j 39.6 | 60.4 Lu I ppm 1 18.2 1 0.641 10.1 1 10.5 1 4.70[ 8.91

32 ROCK SAMPLES

ElementlUnitsl 37 1 38 1 39 I 40 1 41 l 42 Si02 I % [ 54.7 1 59.1 1 54.8 [ 59.0 1 59.5 1 60.8 A1203 % 19.2 1 15.6 1 20.8 1 15.3 I 15.4 1 13.8 CaO I % i 0.47j 2.421 0.821 1.391 1.651 0.54 Vigo I X I <0.011 0.201 0.331 0.071 0.081 0.03 Na2O % 1 9.421 8.341 9.691 11.5 1 12.101 8.44 K20 i % 1 5.141 2.871 2.561 1.751 1.011 3.48 Fe203 1 % i 3.691 9.581 1.891 6.521 7.491 10.5 MnO I % 1 0.311 0.281 0.271 0.521 0.471 0.24 TiO2 I % 1 0.231 0.531 0.111 0.261 0.251 0.34 P205 1 % 1 0.171 0.131 0.131 0.051 0.171 0.03 LOI I % 1 5.311 0.621 8.541 2.001 1.00! 0.85 SUM % i 99.201 100.0 I 100.4 1 100.3 1 99.121 99.90 i I ~ ~~I I I I I Ag Dppm I <0.5 1 <0.5 1 <0.5 1 <0.5 1 11.6 1 <0.5 As PDo! 13 | 6 | <2 | 57 | 83 | 5 Au fppb <20! <8 <6 ! <20 12 <9 B ppm! 110! 20 ! 40 1 30 I 71 I 20 Ba oppm 410 800 470 310 1 <100 240

Be ppm! 280! 8 220 120 _- 11 Br PPm! <2 1 1 4 <2 1 <5! 2 Cd I ppm <(1.0 <1.0 <1.0 I <1.0 | 11 | <1.0 Co ppm! <2 5 ! <2 <2! <10! 2 Cr ppm! 20 <10! 10 10 ! 130 1 <10 Cs ppm 20.2 1.8 34.6 3.5! <1 1 <1.3 Cu Ppnp I 2.5 I 3.5 ! 1.5 I 1.5 I 9 1 1.0 Ge ppm! 20 <10 20 20 - I <10 Hf ppm! 47 24 29 210 253 1 120 Mn ppm ! 1800 ! 1900 1700 3300 - ! 1400 Mo PPm! <5 1 <5! <5 <5 <4 1 <5 Nb pom! <10 | 50 | <10 | 300 I * I 200 Ni oppm 6! 2! 4 10! <1 I 3 Pb ppm| 98! 6 44! 110 405 10 Rb Dppm 300 70 110 70 32 120 Sb I Dpm | 4.5 <(0.2 | 2.1 | 1.1 | 1.8 I 0.3 Sc I ppm 1 0.2 I 3.0 ! 0.1 I 0.6 1 <0.5 I 0.4 Se ppmo <5 <5 I <5 <5 1 <10 <5 Sr ppm! 10 80 100 20 1 200* <10 Ta ppm! 3! 41 2 11 1 13 10 Th ppm 1400 1 11 | 610 1 140 1 28 | 13 U ! ppm ! 181 1 2.9 1 88.6 1 37.4 1 29 1 7.4 V ppm! 6 8! 4 1 8 1 - 8 W lppm <4 <3 <4 1 <4! <2 <3 Y ppm! 720 170 400 1 1600 1500* 550 Zn ppm 1400 230 1600 1 840 755 360 Zr Dppm I 3200 ! 1300 I 2100 1 12000 I 14000 I 5400 La ppm 1 757 I 64.1 713 496 470 140 Ce ippm 1110 139 956 980 980 315

Nd ppm! 346 94 274 440 _- 152 Sm ppm! 57.6 18.6 36.6 106 145 32.0 Eu ! ppm I 8.8 I 5.0 I 5.8 I 23.2 1 12 I 7.5 Tb ! ppm I 9.6 I 4.3 | 4.1 I 28.1 | 37 I 9.6 Yb I ppm I 35.5 ! 16.8 I 18.2 I 105 I 110 ! 62.5 Lu I ppm I 6.281 2.481 3.181 12.1 1 13 1 8.41 (-)Not analyzed * Elemental interference noted 33 ROCK SAMPLES

ElementlUnitsl 43 1 44 1 45 1 46 1 47 1 48 SiO2 I % 1 61.1 1 71.6 1 62.81 71.1 1 69.9 1 75.4 A1203 I % 1 16.2 1 7.301 15.7 1 8.961 3.901 6.99 CaO I % 1 0.771 0.231 0.421 0.311 0.581 0.77 MgO I % | 0.081 0.031 0.021 <0.011 0.721 0.89 Na2O I % 1 7.631 5.721 8.601 5.271 3.911 2.60 K20 I % 1 4.471 2.391 3.561 3.211 2.111 3.05 Fe203 I % 1 7.621 7.621 6.241 9.691 8.051 3.69 MnO I % 1 0.161 0.171 0.201 0.241 0.361 1.14 TiO2 I % 1 0.321 0.401 0.281 0.521 0.321 0.30 P205 I % I 0.051 0.041 0.031 0.031 0.101 0.12 LOI I X 1 1.231 0.921 1.231 0.231 0.811 2.62 SUM % 1 100.2 1 100.4 1 99.901 99.801 101.2 1 98.90

Ag I ppm I <0.5 I <0.5 <(0.5 <(0.5 I <0.5 <(0.5 As ppm! 7! 41 5! 2 7 I 35 Au |ppb <7 <8! 7! <6 <5! <5 B !ppm! 40 20 1 30 10 1 30 30 Ba ppm 640 120 180 170 150 370 Be ppm! 8 13 101 9 10 66 Br ppm! 4 <1! 2 1 I 2! 4 Cd ppm <1.0! <1.0 2.0 <1.0 <1 | <1 Co ppm! 3 ! 2! 4! 2! 5! 4 Cr ppm <10 I 10! <10! <10 60 30 Cs I ppm I 1.8 I 1.9 <(1.5 1 <1.2 ! <0.9 <(0.5 Cu ppm 1.5 1.0 9.5 1.0 6.0 5.0 Ge !ppm! <10 I <10! <10 <10 30 1 <10 Hf ppm 67 I 400 100 30 I 1200! 110 Mn I ppm I 1000 ! 650 I 1200 I 1700 I 1100 ! 7300 Mo ppm <5 < 5 I <5 <<5 | <5 I <5 Nb |ppm 120 | 290 250 90 130 1200 Ni !ppm! 4 I 2! 3! 5 17! 9 Pb ppm 18 I 58 | 14 <(2 1 54 I 88 Rb ppm 130 | 110 80 80 ! 100 150 Sb I ppm I 0.2 | 1.2 ! 0.3 ! 0.8 I 24 | 17 Sc I ppm I 1.1 ! 0.2 1 0.5 1 0.2 I 1.6 I 1.6 Se ppm <5 I 60! <5 <5 <3! <3 Sr !ppm 20 I <10! <10! <10! <10 70 Ta !ppm! 6 I 11 17! 4! 8 24 Th ppm 12 ! 32 | 23 1 15 | 260 | 180 U I ppm I 5.1 I 50.7 I 20.7 I 5.8 1 158 ! 240 V ppm 10 I 10 10 10 I 26 1 20 W ppm <3 I 14 <<3 (3 1 <3 <3 Y ppm 370 ! 1400 350 270 1400 2400 Zn ppm 270 I 320 450 230 120 4600 Zr I ppm I 2900 I 27000 1 5200 I 1300 I 75000 ! 5500 La I ppm I 73.5 I 10.1 I 25.0 I 68.0 ! 30.8 I 552 Ce ppm 282 I 271 93 156 228 1120 Nd ppm 72 | 20 I 22 70 76 507 Sm I ppm I 19.6 I 9.2 I 6.2 1 16.0 1 17.7 1 131 Eu I ppm I 4.6 I 2.5 1 1.3 I 3.6 1 6.3 I 29.3 Tb I ppm ! 5.9 | 11.4 I 4.4 1 6.0 | 15.7 | 35.8 Yb I ppm ! 39.9 I 230 1 42.8 | 23.5 1 198 I 121 Lu I ppm I 5.22 1 30.1 1 6.211 3.711 32.6 1 17.2

34 APPENDIX B

Heavy mineral concentrates multi-element analyses

35 HEAVY MINERAL CONCENTRATES

ElementlUnits! 1 I 2 I 3 I 4 I 5 I 6 Ag Ippm< <5 <51 <5 1 <5 1 <5 1 <5 As lppml 5 1 10 24 1 9 13 1 6 Au |ppb 30 20 1 20 1 <10 I 10 1 10 Ba Ippm 400 1 200 1 700 1 200 1 500 1 300 Br Ippml 15 1 11 I 3 1 41 8 1 7 Co Ippml 32 1 37 1 34 1 33 1 27 I 28 Cr Ippm1 180 1 240 1 210 1 210 1 170 1 140 Cs Ippm 0.81 1.01 1.61 <0.51 1.41 1.0 Fe I pct j 8.711 7.471 8.531 8.351 5.891 6.81 Hf Ippml 4! 4 1 3 1 4 1 3 1 3 Mo lppml <5 1 <5 1 5I 6 1 6 1 5 Na I ppm 1 21000 I 17000 I 20000 I 21000 I 24000 I 27000 Ni I ppm I <200 | <200 1 <200 I <200 I <200 I <200 Rb Ippml 30 20 <20 20 1 40 30 Sb I ppm I 2.7 I 0.7 I 0.9 I 0.4 I 0.5 | 0.4 Sc I ppm I 25.9 I 25.7 I 25.8 I 26.5 I 23.7 I 24.1 Se IppmI <3 <31 <3 1 <3 1 <3 1 <3 Sr I ppm I <500 I <500 I <500 I <500 I <500 I <500 Ta lppml 1 1 1 1 <1 1 1 <1 Th I ppm | 2.2 | 2.3 | 2.3 | 2.9 I 2.1 I 1.2 U I ppm I 2.7 I 1.5 I 1.5 I 1.0 I 1.4 I <0.5 W Ippml <3 1 <3 1 <3 <3 31 <3 Y ppm! 25 1 26 1 25 1 33 1 23 1 32 Zn lppml 90 1 150 1 70 1 100 1 130 1 120 La I ppm 1 15.1 I 14.6 I 12.7 I 18.2 I 12.5 I 8.9 Ce ppm! 32 1 36 1 28 42 1 30 1 25 Nd lppm| 17 1 14 1 15 1 17 1 14 1 13 Sm I ppm I 3.3 I 3.1 I 3.3 I 4.3 I 3.0 I 2.7 Eu I ppm I 1.5 I 1.2 I 1.3 I 1.8 I 0.9 I 1.1 Yb Ippm I 1.9 I 2.1 I 2.2 | 2.4 | 2.5 | 2.5 Lu I ppm 0.281 0.351 0.351 0.391 0.391 0.36

36 HEAVY MINERAL CONCENTRATES

ElementlUnitsl 7 1 8 1 9 1 10 I 11 1 12 Ag Ippml <5 1 <5 1 <5 <5 1 <5 [ <5 As lppml 32 1 45 34 1 9 1 5 1 10 Au !ppb 10 10 1 100 10 10 <10 Ba !npm 6001 1500 1100 1 300 <150 1 400 Br ippml 7l 4! 81 4 1 4 1 3 Co !ppml 37 33 1 31 1 30 1 49 21 Cr Ippm 230 1 280 1 290 1 120 1 98 1 240 Cs Ippm 0.91 0.81 0.71 <1.0 1.9 1.1 Fe I pCt I 9.731 10.1 1 7.851 30.4 1 30.4 1 10.2 Hf Ippm3 3 3 1 4 1 41 1 2 1 11 Mo !ppml 7 1 14 1 10 1 5 1 <5 l 12 Na I ppm I 20000 I 13000 I 16000 I 26000 I 28000 I 16000 Ni I ppm I <200 I <200 I <200 I <200 I <200 I <200 Rb Ippm 30 20 1 30 1 <20 1 <20! 30 Sb I ppm I 0.9 I 2.1 | 0.9 I 0.4 I 0.3 | 0.9 Sc I ppm I 21.5 I 20.1 I 24.1 I 12.5 I 20.9 I 35.0 Se Ippml <3 1 <3 1 <3 1 <3 1 <3 1 <3 Sr I ppm I <500 I <500 I <500 I <500 I <500 l <500 Ta Ippm <1<1 (< i <1i 2 1 <1 I 1 Th I ppm I 3.7 I 2.3 I 3.3 I 10 I 1.3 I 3.4 U I ppm I 1.9 I 3.2 I 2.9 I 6.7 I 0.9 I 3.3 W ppm< <3 31 <3 1 <3 1 <3 1 3 Y Ippm! 36 1 32 1 38 250 20 I 72 Zn ppm! 90 1 180 130 1 110 1 60 160 La I ppm I 32.0! 13.6 19.61 28.3 7.7 I 21.8 Ce ppm! 57 1 32 1 42 1 81 1 20 1 57 Nd !ppml 24 17 I 17 1 30 8 I 30 Sm l ppm I 4.6 3.0 3.9 I 8.3 I 2.3 I 7.3 Eu I ppm I 2.0 1 0.9 I 1.2 I 2.8 I 1.0 I 2.5 Yb !ppm 2.41 2.31 2.8 18.6 2.0! 7.9 Lu I ppm 1 0.381 0.391 0.481 2.791 0.311 1.20

37 HEAVY MINERAL CONCENTRATES

ElementlUnitsl 13 | 14 1 15 1 16 1 17 1 18 Ag Ippml <5 1 <5 1 <5 1 <5 1 <5 1 <5 As Ippml 6 1 191 8 I 12 1 5 19 Au lppb 10 1 <10 1 20 20 1 40 1 <10 Ba Ippm 900 1 700 1 400 1 500 1 700 600 Br Ippml 2 I 3 2 1 1i 2 1 9 Co Ippml 3 1 9 1 4 1 5 1 3 1 33 Cr Ippm 100 1 170 1 120 1 150 1 75 1 170 Cs I ppm I 0.9 I 1.2 I 1.7 I 0.9 I <0.9 I 1.0 Fe I pct I 10.2 I 8.161 10.3 1 16.1 1 8.791 7.22 Hf Ippml 30 1 55 1 69 1 130 1 54 1 3 Mo lppm< < I < I <5 1 <5 1 <5 1 <5 Na I ppm I 48000 I 45000 I 44000 I 39000 I 54000 | 18000 Ni I ppm I <200 I <200 1 <200 I <200 I <200 I <200 Rb fppml 30 70 30 30 30 20 Sb Ippm 1.3 0.81 0.4 1.0 0.6 0.7 Sc I ppm I 6.3 I 8.4 I 8.1 I 11.4 I 4.4 I 34.5 Se Ippm <3 I <3 I <3 I <3 I <3 I <3 Sr I ppm I <500 I <500 I <500 I <500 I <500 1 <500 Ta Ippml 2 1 4 1 3 1 6 1 2 1 <1 Th I ppm I 5.0 | 16 I 19 | 33 I 14 | 2.3 U I ppm I 3.0 I 10.5 I 8.7 I 19.6 I 6.9 I 2.5 W Jppmj <3 1 <3 <3 1 <3 1 <3 <3 Y Ippm 160 1 260 1 390 1 770 1 270 1 44 Zn Ippm 160 1 170 1 170 1 290 1 150 1 190 La I ppm I 46.7 I 43.4 I 63.5 I 70.1 I 46.6 I 16.0 Ce Ippm 122 1 128 1 1481 205 1 132 1 35 Nd Ippml 66 56 83 104 66 | 17 Sm pppm I 15.01 11.91 18.01 25.31 15.01 4.3 Eu lppm 4.41 4.01 5.01 6.51 4.21 1.8 Yb I ppm I 18.6 | 24.3 I 32.9 | 64.6 I 26.5 1 3.3 Lu I ppm 1 3.151 3.551 5.301 9.771 4.381 0.49

38 HEAVY MINERAL CONCENTRATES

ElementlUnitsl 19 1 20 1 21 1 22 ! 23 ! 24 Ag IppmI <5 5 <51 <5 1 <5 1 <5 As lppml 24 1 16 1 15 | 10G 5 1 9 Au lppb 10 30 10 1 <10 10 1 <10 Ba Ippm 400 1 400 1 400 1 500 1 800 900 Br lppml 12 1 5 1 7 1 7! 3 1 2 Co lppm1 25 1 31 1 25 1 8 1 5 1 4 Cr ppm 140 1 210 1 240 170 1 200 1 87 Cs Ippml 1.]1 1.71 1.41 1.61 1.01 0.8 Fe I pct 1 6.451 7.151 7.051 6.931 10.5 1 6.77 Hf ppm 2 1 3! 5 41 1 47 I 36 Mo ppm! <5 | 5 <5 1 <5 | 5 1 <5 Na I ppm I 21000 I 29000 I 28000 I 47000 1 50000 56000 Ni I ppm 1 <200 I <200 I <200 I <200 I <200 1 <200 Rb ppm! 30 20 I 40 1 60 1 50 50 Sb I ppm 1 0.4 1 0.2 | 0.4 | 0.3 | 0.3 0.4 Sc fppm 28.61 28.01 33.41 9.71 5.81 4.3 Se ppm! <3 <3 <3 1 <3 1 <3 1 <3 Sr I ppm I <500 1 <500 I <500 I <500 I <500 I <500 Ta Ippml <1 <1 < <1 i 3! 2 1 <1 Th I ppm I 2.1 | 1.9 | 2.8 10.0 | 5.7 I 7.3 U I ppm 1.6 I 2.3 I 1.7 I 5.6 i 3.0 I 2.6 W Ippmj <3 1 <3 1 <3 1 <3 1 <3 1 <3 Y ppm! 30 1 31 1 47 1 260 1 240 1 180 Zn Ippm 190 I 200 1 170 1 150 1 230 1 160 La I ppm 1 13.5 I 13.0 I 19.4 I 46.6 I 54.6 I 51.1 Ce ppm! 29 1 29 1 39 111i 1 112 1 107 Nd ppm 19! 15 20 1 55 1 79 68 Sm I ppm I 3.3 I 3.6 I 4.5 I 13.4 I 16.6 1 14.5 Eu Ippm 1.2 1.3 1.81 3.7 4.71 4.4 Yb I ppm I 2.3 | 2.3 | 3.8 | 20.5 | 20.2 I 17.1 Lu I ppm 1 0.34 1 0.341 0.591 3.021 3.451 2.65

39 HEAVY MINERAL CONCENTRATES

ElementlUnitsl 25 1 26 l 27 I 28 1 29 30 Ag ppm <5 <5 <1 (5 <5 As 7ppml 7 16 1 6 5 9; 5 Au Ppbl 20 20 30 70 1 10 1 10 Ba !ppmrn 4001 700 200 700 1 600 500 Br lppml 21 41 5 4 1 l 5 Co ppml 41 71 11 l 16 l 3 l 5 Cr Ipprml 130 1 110 1 140 1 140 1 97 210 Cs ppm 1.71 1.11 1.21 1.11 0.8 1.8 Fe I pct I 8.421 9.451 4.241 6.131 15.2 1 12.0 Hf Ippm 43 46 1 41 10 1 82 99 Mo ppml <5 l <5 I 5 7 <5< I <5 Na I ppm I 49000 l 51000 I 39000 I 36000 l 52000 I 49000 Ni l ppm l <200 l <200 (<200 <200 l <200 l <200 Rb ppml 30 l 50 l <20 I 30 | 30 I 40 Sb I ppm l 0.2 l 0.6 l 0.4 l 1.0 l 0.3 | 0.4 Sc I ppm l 6.3 l 7.a I 17.0 I 20.7 I 7.1 l 5.3 Se ppml <3 1 <3 <3 1 <3 <31 <3 Sr I ppm I <500 I <500 I <500 1 <500 <500 I <500 Ta Ippm 2 2 <1 1 1 I 21 4 Th I ppm I iC I 9.2 | 3.2 I 4.5 I 10 ! 20 U Ippm I 4.2 I 4.9 I 2.] 1 2.9 I 4.3 l 11.6 W Ippml <3 1 <3 <3 <3 <3 <3 Y Ippm 230 1 190 54 1 64 250 520 Zn lppml 150 270 90 1 270 1 200 1 200 La l Ppm I 45.81 49.31 21.31 26.9 79.41 57.9 Ce Ippml 116 1 120 47 57 l 180 172 Nd lppml 52 74 26 1 32 110 1 69 Sm I ppm I 13.3 I 14.9 I 5.7 I 5.8 1 23.1 l 18.6 Eu ippm 3.71 4.1! 1.9l 1.81 5.41 5.1 Yb I ppm | 21.41 18.41 4.7 6.3 30.61 45.6 Lu I ppm 1 3.651 2.951 0.731 1.001 5.301 6.93

40 HEAVY MINERAL CONCENTRATES

ElementIlUnitsl 31 j 32 i 33 i 34 i 35 l 36 l 37 j Ag jppmnj <51 <5 <5(<5 (<5 (51

As ppm ! 4! 8 i 91 <21 9 110 - I Au !ppb! <10 20 1 <10 <10Q <10 1 10 Ba ppm! 300 400 700 400 200 1000 i Br ppmj 3 ! 15 13! 2! 6! 5! Co !ppm! 5 22 37 17 31! 891----! Cr ppml 230 1 230 190 130 200 220! ---- Cs l ppm j 1.1 l 1.0 <(0.9 i <0.7 l <0.5 i <0.5 i --- i Fe j pct l 14.7 | 6.45! 7.231 5.351 7.451 19.3 i __ Hf ppm 170 12 ! 3 2 l 3! 3 i -__ Mo ppmj 17 j <5! 6 ! 5 i 5 14 l -_- Na I ppm 4E000 j 33000 j 25000 j 27000 37000 j 17000 j ---- Ni ppm <2001 <200 <200! <200! <200! <200! ---- j Rb ppml <20 20 <20 <20 ! <20 20! ---- i Sb ppm 1 0.3 ! 0.2 <(0.2 <0.2 <<0.2 i 2.5 I __ Sc j ppm i 8.0 l 28.7 j 30.5 l 22.5 I 33.8 I 34.2 i ---- Se ppmi <3 <3 i <3 I (3 j <3 j <3 l __ i Sr ppm <500 <500! <500 ! <500! <500 <500 i Ta ppn! 7 i 1 <1 1 1 <1 1 <1 1 <2! Th ippm j 35 j 5.4 j 2.5 | 1.3 ! 1.1 1 1.8 | <2 j U l ppm l 18.1 l 5.8 ! 1.6 j 1.2 i 1.2 i 2.9 l <2 j W ppm <3 l <3! <3 i <3 <3 1 <3 j <31 Y ppml 980 78 33 35 40 41 j 98! Zn ppm! 230 140 180 110! 140 240j j La ! ppm j 63.3 i 21.9 I 13.9 j 10.5 I 15.2 I 14.2 I 30 I Ce ppm 231 j 46 33 25 33 30 83! Nd ppm! 53 22 14 11 | 22 17 I _- i Sm j ppm i 23.4 l 4.9 l 3.8 j 3.1 l 4.3 i 4.0 l Eu ! ppm j 6.1 l 1.4 j 1.2 j 1.1 j 1.8 i 1.5 j _ j Yb i ppr i 83.1 i 7.1 j 3.1 l 2.4 j 2.6 j 2.8 j ---- | Lu ppm 12.] 1 1.051 0.521 0.381 0.38! 0.44! ---- I

41

ASD-FPP- 148-9CI